Field
Exemplary embodiments relate to a display device.
Discussion of the Background
Various display devices have been developed to display information. Some of these display device include a liquid crystal display device (LCD), a plasma display panel (PDP), an electrophoretic display device, and an organic light emitting display (OLED) device. Regardless of the exact display device, these devices include a display panel for displaying an image and a driving circuit unit for driving the display panel.
The driving circuit may be connected to the display panel by a tape carrier package (TCP) method or a chip-on-glass (COG) method. In the TCP method, a driving integrated circuit is attached to a tape that is attached to the display panel. In the COG method, a driving integrated circuit is directly attached to a substrate of the display panel. Lately, more display devices have been made with driving circuits attached to the display panel according the COG method. The COG method is advantageous because it helps reduce the area occupied the driving integrated circuit while also helping to reduce the cost of manufacturing display devices.
A display device using the COG method includes attaching the driving integrated circuit on a chip mounting region of the substrate. The chip mounting region includes output pads electrically connected to output bumps of the driving integrated circuit and input pads electrically connected to input bumps of the driving integrated circuit to supply external signals to the driving integrated circuit.
After the display panel is manufactured, a driving test is performed on the manufactured display panel. The display device using the COG method is formed by including test pads and shorting bars in the chip mounting region to perform the driving test. The driving test determines whether the display panel is driven by applying test signals to the test pads connected to the shorting bars through the shorting bars in a state where the driving integrated circuit is not mounted in the chip mounting region.
Consumers demand thinner and more compact display devices that require thinner and more compact display panels. For display panels to meet these consumer demands, the driving integrated circuit needs to be reduced. Thus, much research is needed in order to reduce the area of the chip mounting region formed on the substrate in accordance with the size of the driving integrated circuit.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.